Approximately 15-20% of women experience postpartum depression (PPD), which results in significant suffering for new mothers and their families, and has an adverse impact on infant development. Fortunately, effective treatments for PPD have been developed and validated. However, there are many barriers that make it difficult for women with PPD to access clinic-based mental health treatments and participation is low. Less than 50% of women with PPD seek help because of psychological barriers (stigma, feelings of failure and embarrassment); knowledge barriers (poor understanding about impact of PPD on infant health, unsure about where to get treatment); infrastructure barriers (fear of negative judgment from pediatrician, avoidance of prescription medications while breastfeeding); physical barriers in rural settings (too few providers of care, unacceptable logistical demands on time, transportation, and childcare); and provider-level barriers (inadequate skills for treating PPD, fear of liability, dearth of treatment options, and inadequate reimbursement). Thus, it is of critical importance to develop innovative service delivery systems that overcome barriers to quality healthcare and reduce health disparities. To address this need, we developed and tested the MomMoodBooster program (MMB), an innovative Web-based program for treating PPD adapted from an evidence-based cognitive-behavioral therapy for depression. The MMB program guides participants through six weekly sessions. Webpages in each session use text, interactions, animations, and video to present program content. The MMB program includes daily tracking and charting of mood and pleasant activities as well as online access to a library, covering a range of issues of concern to new mothers. To enhance supportive accountability, mothers also receive a series of up to six personal coach calls lasting approximately 20 minutes each. In Phase I, we will improve the flexibility of MMB's underlying infrastructure and its administrative website as well as its personal coach features in order to translate the research-focused MMB program into a commercial-ready product that fits the workflow and staffing of healthcare organizations. We will use an iterative formative development process informed by stakeholder input and usability testing by care providers in OB/GYN and family-physician practices. In Phase II, we will add mobile technology to enhance the push aspects of the program and develop an improved administrative interface to enable users in medical care organizations to customize features of the program to meet the needs of their different real-world scenarios. We will also explore the possibility that MMB can be linked to prominent electronic medical record systems that could encourage its greater routine use. Finally, we will use a 2-arm pragmatic randomized controlled trial to evaluate the extent to which healthcare barriers for women with PPD can be overcome by the reach, effectiveness, adoption, implementation, and maintenance of the integrated Web/Mobile MMB program in medical care settings.